drm/i915: Force DPLL calculation for TC ports after readout
We always allocate two DPLLs (TC and TBT) for TC ports. This is because we can't know ahead of time wherher we need to put the PHY into DP-Alt or TBT mode. However during readout we can obviously only read out the state of the DPLL that the port is actually using. Thus the state after readout will not have both DPLLs populated. We run into problems if during readout the TC port is in DP-Alt mode, but we then perform a modeset on the port without going through the full .compute_config() machinery, and during said modeset the port cannot be switched back into DP-Alt mode and we need to take the TBT fallback path. Such a modeset can happen eg. due to cdclk reprogramming. This wasn't a problem earlier because we did all the DPLL calculations much later in the modeset. So even if flagged a modeset very late we'd still have gone through the DPLL calculations. But now all the DPLL calculations happen much earlier and so we need to deal with it, or else we'll attempt a modeset without a DPLL. To guarantee that we always have both DPLLs fully cal/ulated for TC ports force a full modeset computation during the initial commit. v2: Avoid bitwise operation on bool (Jani) Call the return variable 'fastset' to convey its meaning Reported-by: Lee Shawn C <shawn.c.lee@intel.com> Fixes: b000abd3 ("drm/i915: Do .crtc_compute_clock() earlier") Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220922191236.4194-1-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com> (cherry picked from commit eddb4afc) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Showing
Please register or sign in to comment